Smalltalk Zero
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Currently traits have a property called requires: which is an array of method signatures. We need a way to specify more than just implementations that must exist for a class to be part of a trait group. Let's segway a moment and figure out what a class even
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Breaking down the class definition we have a problem: list = { class | parameters: (of: object-t,), constants: (element-class: of,), traits: (sequenceable-t of: element-class,), variables: ( elements: &array of: element-class, length: uint, allocator: &memory-allocator,) } The constants section references a variable that doesn't exist. The traits section references a variable that
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Just as an side back to the getters and setters of Person's name. My intention is that declaring the class auto-creates the getter and setter for you. Person = ( name: string, age: (quantity of: seconds) ) However, how do you specify which variables you want to be public and which
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One of the hallmarks of Smalltalk code is sending 'new' to a class. This creates you a new object that you can then configure with message sends, eg: Person new name: 'Jane'; height: 5 foot + 6 inches; yourself If we were to use this approach for
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For my own sanity, now that the examples are getting more complicated, I really needed some syntax highlighting support for the language. I need it in two places - here in ghost, the blogging software I use, and in zed.dev the editor i'm using. This was a
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Since I'm trying to write example code I have found it annoying that I don't have syntax highlighting. My editor of choice these days is zed which uses tree-sitter as its parser. I suppose I could take everything we know and try to make a parser
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One of the cool features of the maybe pattern is how some values have a 'not instantiated' state by default - such as pointers. A memory-address of 0 can mean 'there is no pointer' while any other value means there is a pointer. The default maybe
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A controversial topic in the programming world - how do you end a statement? In Smalltalk you do it with a fullstop . In C you do it with a ; In Javascript you do it with a ; unless you don't because sometimes it knows what you mean. In Python
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Now that we have traits, interfaces, generics, poly types ... we'll just call them traits until I realise that's the wrong word ... we can move on to the burning question in my mind. How the heck do we implement array? array = (address: memory-address, length: uint,) Great! That
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I posed the question - if we have the ability to do traits then should we not favour it over inheritance? The answer is about simplicity of understanding the code and also writing it. Freedom of expression is great but freedom from other peoples excessive expression also has its merits.
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Before we can write an interpreter or compiler we need to be able to parse the syntax of stz. The rules are fairly simple so far. There's a few characters that are special: start-bracket ( stop-bracket ) start-block [ stop-block ] start-make { stop-make } divider | return ^ string-quote ' " ` reference & keyword-break : comment-start
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Writing out enumerated values should be as simple as listing them. For instance: north = 1 east = 2 south = 3 west = 4 The whole point of enums though is to scope them away inside a namespace. To use the enum as a type. The problem with throwing random names out there